The Derwent is a river in Tasmania, Australia. It was named after the River Derwent, Cumbria by British Commodore John Hayes who explored it in 1794. The name is Brythonic Celtic for "valley thick with oaks"^[1][2].

The banks of the Derwent were once covered by forests and occupied by Aboriginals. European settlers farmed the area and during the 20th century many dams were built on its tributaries.

History

The River Derwent was inhabited by the Mouheneener people ^[3] for at least 8000 years before British settlement. Evidence of their occupation may be found in many middens along the banks of the river. The Mouheneener people's name for the river is Teem.toomele men.en.nye.

When first explored by Europeans, the lower parts of the picturesque valley were clad in thick she-oak forests, remnants of which remain in various parts of the lower foreshore.^[4]

There was a thriving whaling industry until the 1840s when the industry rapidly declined due to over-exploitation.^[5]

Geography

The river originates at Lake St Clair and flows south over a distance of 187 km to New Norfolk and the estuary portion extends a further 52 km out to sea. Flows average in range from 50 to 140 cubic metres per second. Mean annual flow is 90 cubic metres per second. ^[4]

The Derwent River

Little Pied Cormorants on the Derwent River

Bridges

Several bridges connect the western shore (the more heavily populated side of the river) to the eastern shore of Hobart – in the greater Hobart area, these include the five lane Tasman Bridge, near the CBD, just north of the port; the four lane Bowen Bridge; and the two lane Bridgewater Bridge and Causeway. Until 1964 the Derwent was crossed by the unique Hobart Bridge, a floating concrete structure just upstream from where the Tasman Bridge now stands.^[7] Travelling further north from the Bridgewater crossing, the next crossing point is New Norfolk Bridge, slightly north of the point where the Derwent reverts from salt water to fresh water, Bushy Park, Upper Meadowbank Lake, Lake Repulse Road, Wayatinah, and the most northerly crossing is at Derwent Bridge, before the river reaches its source of Lake St Clair. At the Derwent Bridge crossing, the flow of the river is generally narrow enough to be stepped across.

Land use

The Upper Derwent is affected by agricultural run-off, particularly from land clearing and forestry. The Lower Derwent suffers from extremely high levels of heavy metal contamination in sediments. The State Government-backed Derwent Estuary Program points out in particular that levels of mercury, lead, zinc and cadmium exceed national guidelines. They also recommend against consuming shellfish and caution against consuming fish in general. ^[4] A large proportion of the heavy metal contamination comes from major industries that discharge into the river: an electrolytic zinc smelter at Lutana established in 1917, and a paper mill at Boyer which opened in 1941. ^[4]

Cultural references

The river is the subject of the multimedia performance "Falling Mountain" (2005 Mountain Festival), a reference to the mountain in the Cradle Mountain-Lake St Clair National Park from which the river rises.

See also

• Hobart Ferry Services

References

1. ↑ Names of Rivers
2. ↑ Celtic Place Names
3. ↑ Parliament of Tasmania - House of Assembly Standing Orders "We acknowledge the traditional people of the land upon which we meet today, the Mouheneener people."
4. ↑ ^{a b c d}
5. ↑ A History of Shore-Based Whaling
6. ↑ http://www.hydro.com.au/Storages/Storage.pdf
7. ↑ Parliament of Tasmania History site - Hobart to Tasman Bridge

External links

• Derwent Estuary Program
• Upper Derwent Issues

cs:Derwent de:Derwent River (Tasmanien) fr:Derwent River